RESUMO
BACKGROUND: Epidemiologic studies suggest a relationship between maternal nutrition during pregnancy and the occurrence of asthma and atopic conditions during childhood. However, individual study results are conflicting. The objective of this meta-analysis was to critically examine the current evidence for an association between nutrition (dietary patterns, food groups, vitamins, or oligo-elements) ingestion during pregnancy and asthma, wheeze, or atopic conditions in childhood. METHODS: The inclusion criteria were as follows: (i) systematic recording of diet during the gestational period and (ii) documentation of asthma, wheezing, eczema, or other atopic disease in the offspring. The primary outcomes were prevalence of asthma or wheeze among the offspring during childhood; and secondary outcomes were prevalence of eczema, allergic rhinitis, or other atopic conditions. RESULTS: We found 120 titles, abstracts, and citations, and 32 studies (29 cohorts) were included in this analysis. Data on vitamins, oligo-elements, food groups, and dietary patterns during pregnancy were collected. A meta-analysis revealed that higher maternal intake of vitamin D [odds ratio (OR) = 0.58, 95% confidence interval (CI) = 0.38-0.88], vitamin E (OR = 0.6, 95% CI = 0.46-0.78), and zinc (OR = 0.62, 95% CI = 0.40-0.97) was associated with lower odds of wheeze during childhood. However, none of these or other nutrients was consistently associated with asthma per se or other atopic conditions. CONCLUSIONS: Current evidence suggests a protective effect of maternal intake of each of three vitamins or nutrients (vitamin D, vitamin E, and zinc) against childhood wheeze but is inconclusive for an effect on asthma or other atopic conditions.
Assuntos
Asma/epidemiologia , Hipersensibilidade Imediata/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Fenômenos Fisiológicos da Nutrição Pré-Natal , Sons Respiratórios/etiologia , Asma/etiologia , Dieta/efeitos adversos , Feminino , Humanos , Hipersensibilidade Imediata/etiologia , Razão de Chances , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Prevalência , Fatores de RiscoRESUMO
BACKGROUND: Risk factors for wheezing specifically during the first year of life have been studied in well-developed countries, but the information from developing countries is very scarce. There are no such studies focusing on factors derived from poverty. The aim of the present study was to determine if risk factors related to poverty are associated to wheezing during the first year of life in infants from Honduras and El Salvador. METHODS: A survey, using a validated questionnaire, was carried out in the metropolitan area of San Pedro Sula (Honduras) and in La Libertad (El Salvador) in centres where infants attended for a scheduled vaccination shot or a healthy child visit at 12 months of age. Fieldworkers offered questionnaires to parents and helped the illiterate when necessary. The main outcome variable was wheezing during the first year of life, as reported by parents. RESULTS: A total of 1047 infants in El Salvador and 780 in Honduras were included in the analysis. The prevalence of wheeze in the first year was higher in El Salvador (41.2%) than in Honduras (27.7%), as was recurrent wheezing defined as three or more episodes (18.4% vs. 11.7%). Wheezing and recurrent wheezing was associated to unpaved floor in the household (summary odds ratios for both countries 1.55, p=0.036 and 1.72, p=0.054 for any wheeze and recurrent wheezing, respectively); dust entering from streets (1.30, p=0.052 and 1.67, p=0.008); living in a heavily polluted area (1.33, p=0.037 and 1.52, p=0.033); and having mould stains on the household walls (1.36, p=0.072 and 1.76, p=0.007). Furthermore, marginal associations were found for additional person at home and use of kerosene as cooking fuel. University studies in the mother (0.34, p=0.046 and 0.32, p=0.022) and a professional occupation in the father (0.34, p=0.046 and 0.26, p=0.047) were associated to a lower risk. CONCLUSIONS: The prevalence of wheezing and recurrent wheezing is notoriously high in El Salvador and Honduras. In those populations factors related to poverty are associated to a higher prevalence of wheezing and recurrent wheezing, whereas higher maternal education and paternal professional occupation behave as protective factors.
Assuntos
Pobreza , Transtornos Respiratórios/epidemiologia , Poluentes Atmosféricos/efeitos adversos , Poeira , Educação , El Salvador , Honduras , Humanos , Lactente , Recém-Nascido , Prevalência , Transtornos Respiratórios/diagnóstico , Transtornos Respiratórios/fisiopatologia , Sons Respiratórios , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Common polymorphisms have been identified in genes suspected to play a role in asthma. We investigated their associations with wheeze and allergy in a case-control sample from Phase 2 of the International Study of Asthma and Allergies in Childhood. METHODS: We compared 1105 wheezing and 3137 non-wheezing children aged 8-12 years from 17 study centres in 13 countries. Genotyping of 55 candidate single nucleotide polymorphisms (SNPs) in 14 genes was performed using the Sequenom System. Logistic regression models were fitted separately for each centre and each SNP. A combined per allele odds ratio and measures of heterogeneity between centres were derived by random effects meta-analysis. RESULTS: Significant associations with wheeze in the past year were detected in only four genes (IL4R, TLR4, MS4A2, TLR9, P<0.05), with per allele odds ratios generally <1.3. Variants in IL4R and TLR4 were also related to allergen-specific IgE, while polymorphisms in FCER1B (MS4A2) and TLR9 were not. There were also highly significant associations (P<0.001) between SPINK5 variants and visible eczema (but not IgE levels) and between IL13 variants and total IgE. Heterogeneity of effects across centres was rare, despite differences in allele frequencies. CONCLUSIONS: Despite the biological plausibility of IgE-related mechanisms in asthma, very few of the tested candidates showed evidence of association with both wheeze and increased IgE levels. We were unable to confirm associations of the positional candidates DPP10 and PHF11 with wheeze, although our study had ample power to detect the expected associations of IL13 variants with IgE and SPINK5 variants with eczema.
Assuntos
Estudos de Associação Genética , Hipersensibilidade/genética , Sons Respiratórios/genética , Alérgenos/imunologia , Ásia , Asma/genética , Criança , Proteínas de Ligação a DNA/genética , Dipeptidil Peptidases e Tripeptidil Peptidases/genética , Equador , Eczema/genética , Europa (Continente) , Frequência do Gene/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Humanos , Hipersensibilidade/sangue , Hipersensibilidade/imunologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Interleucina-13/genética , Subunidade alfa de Receptor de Interleucina-4/genética , Desequilíbrio de Ligação/genética , Receptores de Lipopolissacarídeos/genética , Nova Zelândia , Polimorfismo de Nucleotídeo Único/genética , Proteínas Secretadas Inibidoras de Proteinases/genética , Receptores de IgE/genética , Sons Respiratórios/imunologia , Rinite Alérgica Perene/genética , Rinite Alérgica Sazonal/genética , Inibidor de Serinopeptidase do Tipo Kazal 5 , Testes Cutâneos , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genética , Receptor Toll-Like 9/genética , Fatores de Transcrição/genética , Fator de Crescimento Transformador beta1/genética , Fator de Necrose Tumoral alfa/genéticaRESUMO
BACKGROUND: Although the treatment of asthma has been addressed in several guidelines, the management of the first acute wheezing episode in infants has not often been evaluated. We surveyed practicing pediatricians in Spain about the treatment they would provide in a simulated case. MATERIAL AND METHODS: A random sample of 3000 pediatricians and physicians who normally treated children was surveyed. The questionnaire inquired about how they would treat a first mild-to-moderate wheezing attack in a 5-month-old boy with a personal and family history of allergy. Pediatricians were asked about their professional background. RESULTS: A total of 2347 questionnaires were returned with useful data (78.2%). Most (90.4%) of the pediatricians would use a short-acting beta2 agonist (SABA) via a metered-dose inhaler with a spacer and a face mask or nebulizer. However, only 34.5% chose a SABA alone: 31.3% added an oral steroid and 27.6% added an inhaled corticosteroid (ICS). The factors associated with the use of ICS in the acute attack were: (1) lack of specific training in pediatrics (OR 1.45; 1.12-1.85) and (2) primary care health center setting (OR 1.31; 1.01-1.69) or rural setting (OR 1.28; 1.01-1.66). Forty-four percent did not recommend any follow-up treatment while 20.7% prescribed ICS as maintenance therapy. The factors related to this decision were the same as those described above. CONCLUSIONS: The management of a first wheezing episode seems to meet published guidelines among Spanish pediatricians with formal training in pediatrics and in those who work in a hospital setting or in urban areas.